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In this blogpost, Sudhi Ranjan Bagri, Student, National Law Institute University, Bhopal, writes about section 45 of the Indian Evience Act, who is an expert, prerequisites of an expert evidence, difference between expert  and non- expert witness and the evidentiary value of expert witness.


Under section 45, opinions of experts are relevant on questions of foreign law, science, art, identity, handwriting or finger impressions. Expert testimony is admissible on the principle of necessity. The help of experts is necessary when the question  involved is beyond the range of common experience or common knowledge or where the special study of a subject or special training or skill or special experience is called for. No man is omniscient; in fact, perfection is an attribute of divinity only.

As a general rule, the opinion of a judge only plays a part and is thus relevant in the decision of a case, and thus, the opinion of any person other than the judge about any issue or relevant fact is irrelevant in deciding the case. The reason behind such a rule is that if such opinion is made relevant, then that person would be invested with the character of a judge[1]. Thus, Section 45 is thus an exception to this general rule, as it permits the experts opinion to be relevant in deciding the case. The reason behind this is that the Judge cannot be expected to be an expert in all the fields-especially where the subject matters involves technical knowledge[2] as he is not capable of drawing an inference from the facts which are highly technical. In these circumstances, he needs the help of an expert- who is supposed to have superior knowledge or experience in relation to the subject matter.


Section 45, Indian Evidence Act, 1872:

“When the Court has to form an opinion upon a point of foreign law, or of science, or art, or as to identity handwriting or finger impressions, the opinions upon these points of persons especially skilled in such foreign law, science or art or in questions as to identity of handwriting or finger impressions, are relevant facts. Such persons are called experts.”

A fact is something cognizable by the senses such as sight or hearing, whereas opinion involves a mental operation. Under Section 3, the opinion of a person will be a fact too. U/s 60 oral evidence in all cases must be direct if inter alia it refers to an opinion or to grounds on which that opinion is held. It must be the evidence of the persons who hold the opinion on those grounds. A distinction must be drawn, however, between the cases where an opinion may be admissible u/s 6 to 11 as forming a link in the chain of relevant facts to be proved and between cases where opinions are admissible under sections 45-51. The former evidence is given by the non-expert or the unskilled witness while the latter is given by the expert witness. Thus, in matters of calling for special knowledge or experience or skill, opinions of expert witnesses is relevant u/s 45-51.

Prerequisites of an expert evidence

For the sake of consideration of an expert testimony, there are two important conditions that are necessary to be shown:

  1. That the subject is such that expert testimony is necessary.
  2. That the witness in question is really an expert.[3]

It must be proved that the witness is competent enough to give the evidence and that the fact to be proved is a point of science or art of which the witness is an expert in, before the opinion of a person can be admitted in evidence[4].

If a witness is not proved to be an expert, his opinion will become irrelevant.  It must be proved that the witness is an expert. He must be examined as a witness in the Court and be subject to cross-examination[5].

Who is an expert?

Section 45 defines an expert as a person who is especially skilled in a given field. The test of judging the competency of a person is this: “Is it peritus[6]?” Is he skilled? Has he adequate knowledge[7]?

An expert is a person who has special knowledge and skill in a particular calling to which the inquiry relates[8]. An expert witness is one who has devoted time and study to a special branch of learning, thus is especially skilled on those points on which he is asked to state his opinion. His evidence on such points is admissible to enable the tribunal to come to a satisfactory conclusion[9]. The section does not refer to any particular attainment, standard of study or experience, which would qualify a person to give evidence as an expert. All persons who practice a business or profession which requires them to possess certain knowledge of the matter in hand are experts, so far as expertness is required. It is the duty of the judge to decide whether the skill of any person in the matter on which evidence of his opinion is offered is sufficient to entitle him to be an expert.

Opinion is estimation, a belief or assessment, a view held as probable, what one thinks about a particular question or topic, an assessment short of grounds of proofs, a formal statement of reasons for the judgment, a formal statement of professional advice[10].

Difference between an expert and non-expert witness

Like a non expert witness the testimony of an expert witness need not be confined to actual facts and he may give evidence on facts as stated by other witnesses, e.g. a doctor who might not have seen the patient personally can opine as to the cause of his death on facts deposed. He may cite textbooks in support of his opinion or to refresh his memory (S.159); he may speak about experiments made by him in the absence of parties.

The opinion of an expert witness, however, eminent in his field he may be, must not be read as conclusively of the fact which the Court has to try[11]. However, evidence of eminent literary persons as experts can be relied upon.[12]

Competency and credit of an expert

Under section 45 of Indian Evidence Act, the evidence of an expert can be led on a question of foreign law etc., to enable the tribunal to come to a satisfactory conclusion. It is for the Court to decide the competency or fitness of a witness. The test is to see if the witness is sufficiently qualified by experience.[13] His credit can be challenged by cross-examination, or by the contrary evidence of another expert or by showing that he had expressed a different opinion on the same question previously or in any of the modes allowed u/s 146 to 153 and S. 155 to impeach the credit of a witness generally.

The questions put to an expert are generally hypothetical as they assume something for the time being. An expert witness must himself come and give evidence in court. His certificate cannot go in automatically without proof unless permitted by statutory exceptions like s. 509 (medical certificate), or section 510 or the CrPC (report of the chemical analyst).

Expert opinion– evidentiary value

The opinion of an expert must be of corroborative nature to the facts and circumstances of the given case. If the opinion contradicts an unimpeachable eyewitness or documentary evidence, then it will not have an upper hand over direct evidences[14]. The Section does not provide for any specific attainment of knowledge or study or experience for being called an expert. Experts are admissible as witness but, they are not to make conclusion as it is a judicial function[15].

In Forest Range Officer v. P.Mohammad Ali,[16] it was held that expert opinion is only the opinion evidence. It does not help the Court in interpretation. The mere opinion of an expert cannot override the positive evidence of the attesting witness.[17] Expert opinion is not necessarily binding on the Court.[18]

In Murali Lal v. State of Madhya Pradesh,[19]  it was held by the Supreme Court that here is no justification for condemning the opinion evidence of an expert to the same class of evidence as that of an accomplice and insist upon corroboration. The court also stated that it would be a grave injustice to base a conviction solely on the opinion of handwriting expert or any other kind of expert, without substantial corroboration. An expert deposes and not decides. His duty is to furnish the judge with the necessary scientific criteria for testing the accuracy of his conclusion so as to enable the judge to form his own independent judgment by the application of these criteria to the facts proved in evidence[20].

Foreign Law

Law which is not in force in India is foreign law. In England it can be proved by leading expert evidence. In India it may be proved the same way under section 45 or by producing of official books and reports on foreign law u/s 38. Foreign law is, therefore, a question of fact.[21] Hindu Law and Mohamedan Law are laws of the land and it is the duty of the court to interpret the law of the land and hence the opinions of experts however learned will be irrelevant.[22]

Science or Art

The expression Science or Art includes all subjects on which a course of special study or experience is necessary to the formation of an opinion. The words science and art are therefore to be broadly construed; the term ‘science’ not being limited to higher sciences and ‘art’ not being limited to fine arts. To determine whether a particular matter is of a scientific nature or not, the test to be applied is whether the subject matter of inquiry is such that inexperienced persons are unlikely to prove capable of forming a correct judgment without the assistance of experts.

Medical Experts

The deposition of a medical officer in the court and the reports produced by him are considered as evidence. A mere post-mortem report, however, is no evidence since no facts could be taken from it.[23]

Value of Medical Evidence

Expert evidence should be approached with care and caution. An expert witness, however, impartial is naturally biased in favor of the party who calls him. He is often called by one side simply and solely because it has been ascertained that he holds view favorable to his interest.[24] Medical evidence isn’t direct, and, therefore, value of such an evidence lies only on the extent to which it supports and lends weight to the direct evidence of eye-witnesses or contracts that evidence and removes the possibility that the injury could take place in the manner alleged by those witnesses.[25] The opinion of a doctor is entitled to great weight but may be discarded on good grounds.

Opinion of Handwriting Expert

U/s 45 of the Indian Evidence Act an expert can depose to the identity of handwriting between the questioned document and the document admitted or proved. A disputed handwriting may be proved either by calling an expert (S.45) or by examining a person acquainted with the handwriting of the person by whom the questioned document is alleged to have been written (S. 47) or a comparison of the two u/s 73.

However, the opinion of handwriting expert is only made admissible; it is not the only method of proving handwriting.[26] In Fakhruddin v. State of M.P.[27], the SC suggested three modes of proof of document: firstly by Direct evidence, secondly by expert’s evidence and thirdly, by the court coming to the conclusion by comparison[28].


A man’s signature is called an unforgettable signature. This head was added to expert evidence’s scope in 1899. The study of fingerprints is generally admitted to constitute a science. Its two basic hypotheses are that:

Firstly, fingerprints of a person remain the same from birth to death;

Secondly, there has never yet been found any case where pattern made by one finger exactly resembled the pattern made by any other finger of the same or any other hand.

The opinion of thumb impression expert is entitled to greater weight-age than that of a handwriting expert.

Firearms Experts

The opinion of a ballistic expert can conclusively prove that a particular cartridge has been fired by a particular pistol.[29]

Where the ballistic expert has not seen the wound himself but has given his opinion based upon the recordings or photo produced by the doctor who saw or inspected the wound, no reliance can be placed on such an expert opinion.[30] Therefore, the firearms or ballistic expert must have concluded the opinion based on his own findings and personal observation.

Case laws


AIR 1974 SC 639


In this case an Excise Inspector Shri C.D. Misra had raided a liquor shop and discovered drums of liquor. On performing smell test on the samples of liquor procured from the drums kept inside the shop, the Excise Inspector found out that the liquid was illicit liquor. He had further tested the contents of the drums with the aid of litmus paper, hydrometer, and thermometer to determine the strength and composition of the liquid under composition. After such observations, he gave testimony where he opined that the liquor shop had been involved in trading illicit liquor and submitted a detailed report regarding the same.


Whether the Excise Inspector could be considered an expert whose opinion about the nature of the liquid found was opinion evidence admissible under Section 45 of the Evidence Act?


The Court held that he Excise Inspector, who had deposed, at the very outset of his evidence, that he had put in 21 years service as Excise Inspector and had tested lacks of samples of liquor and illicit liquor. Further, he had employed all possible ways to test the samples of the liquor present that time, which were clear tests of his reasonability and prudence.

Thus, the Excise Inspector would be an Expert and the testimony and evidence laid by him regarding the discovery of illicit liquor in the liquor shop would be relevant and admissible before the Court of law.

IN Re: Govinda Reddy & ORS.

AIR 1958 Mys 150

The science of comparison of fingerprints has developed to a stage of exactitude. It is quite possible to compare the impressions taken from the fingerprints of the individuals with the disputed impressions, provided they are sufficiently clear, and enlarged photographs are available. The identification of finger impressions with the aid of a good magnifying glass is not difficult, particularly, when the photos of latent and patent impressions are pasted side by side.

It was held that though the witness did not possess any technical qualification in as much as he had neither obtained a degree nor a diploma in photography, his experience of over 25 years in photography was sufficient enough to call him an expert[31].


Decided On: 06.06.2012


The court finalized that it was not solely relying on the opinion of the handwriting experts. The documents seized from the accused’s house when taken into consideration hinted towards the same conclusion which was similar to the one given by the handwriting expert. Further, the act of abscondance of the accused-petitioner furnishes evidence against him of his being responsible for committing forgery on the said two documents. one typed authorization letter, partially legible, in the name of Mangalu Roy, was also found in the said search, Mangalu Roy being, interestingly, the name of the person, in whose name, letter of authorization, in the present case, was shown to have been issued in order to enable withdrawing of the said sum of Rs. 1,65,000/-. This was yet another circumstantial evidence pointing to the guilt of the accused.


Thus, we may conclude that this provision is based on the principle that as judges are not properly equipped to draw proper inferences from the facts stated by witnesses, it is appropriate that the opinion of an expert must be taken into consideration. But the expert’s opinion is a weak form of evidence, especially in the cases where the sufficiency of knowledge is doubtful.

An opinion or belief may be of an expert or a non-expert. A witness, in order to give an opinion, must be competent and the subject matter must be one in respect of which an opinion is allowed. The subject matters of opinion involves skill in a particular trade or profession or a special knowledge of a particular science or art. However, in matters of age, identity or the condition of a person or thing, the belief of the witness is sometimes accepted when it is based on facts within his own knowledge. A jury, however, is entitled to accept or reject the belief or opinion of any witness.


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[3] Parat v. Bissessar, ILR 39 Cal 245

[4] Raj Kishore v. State, AIR 1969 Cal 321

[5] Balkrishna Das Agarwal v. Radha Devi, AIR 1989 All 133

[6]“Peritus virtute official” i.e. the holder of some official position which requires and, therefore, presumes a knowledge of that law.

[7] U.S. Shipping Board v. Ship “St. Albans” 1931 PC 189

[8] Lawson on Expert Testimony, 2nd Edn, 229.

[9] Powell, 10th Edn, p. 39.


[11] Kamala Kuer v. Ratanlal AIR 1971 All 304

[12] Samaresh Basu v. Amal Mitra 1985 SCC (Cr) 523

[13] Gopeswar v. Biseswar 16 CWN 265 (285)


[15] Field’s, Commentary, “Law of Evidence”, Delhi Law House, 12th Edition, Volume 3

[16] AIR 1994 SC 120

[17] U.Jhansi Lakshmi Bai v. P.Mohammad Ali, AIR 1994 SC 120

[18] Las Society of India v. Fertilizers and Chemicals Travancore Ltd. AIR 1994 Ler. 308

[19] 1980 SCR  (2) 249


[21] Khoday Gangadhara v. Swaminath Mudali 1926 Mad 218

[22] Aziz Bano v. Mohd. Hussain 47 All 823

[23] Ramswarup 6 CWN 98

[24] Divan Singh v. Emperor 43 Cr. LJ 565

[25] Nagindra Bala v. Sunil 1960 Cr LJ 1020 (SC)

[26] State v. Tribikram (1971) 37 Cut LT 714

[27] AIR 1967 SC 1326


[29] Kalua v. State of U.P. 1958 Cr. LJ 30 (SC)

[30] Mohan Singh v. State of Punjab AIR 1975 SC 2161

[31] Evidence: Cases and Materials, by SV Joga Rao, LexisNexis- Butterworths Publication, (2003) at p. 351

[32] MANU/GH/0327/2012

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